4-H Sentence Examples

The salt crystallizes with varying quantities of water, according to the temperature at which crystallization is effected: between - 4° C. and +6° C. with 7H 2 O, between 15° C. and 20° C. with 5H 2 O, and between 25° C. and 31° C, with 4H 2 O.

Sodium aurosulphide, NaAuS 4H 2 O, is prepared by fusing gold with sodium sulphide and sulphur, the melt being extracted with water, filtered in an atmosphere of nitrogen, and evaporated in a vacuum over sulphuric acid.